DALLAS (CBSDFW.COM) – The Dallas police officer who witnessed his partner shoot an unarmed mentally ill man and then lied about what happened afterwards has been punished with a 15-day suspension.

Officer Christopher Watson was placed on restricted duty after home surveillance video showed a different story than what Watson swore to in a signed statement.

The video, taken on October 14, showed the victim, Bobby Bennett, with his arms at his side moments before Officer Cardan Spencer shot him. Both Spencer and Watson claimed Bennett lunged at them with the knife before Spencer fired the shot.

At the same disciplinary hearing, Police Chief David O. Brown stated Officer Watson would be investigated by Internal Affairs. Based on the results of that investigation, IA determined that Watson violated the department’s procedures by immediately approaching a possibly armed person. IA also determined Watson was untruthful in a sworn affidavit. Watson, who has been on the force since January 2008, does have the right to appeal his suspension.

Bennett’s mother initially called police on October 14, to report her son was acting violently and may have had a knife. After he was shot, officers charged him with aggravated assault. Those charges were dropped when surveillance video showed he did not threaten officers with a knife as the officers reported. Bennett, who has been diagnosed as paranoid schizophrenia, spent nearly a month in the hospital recovering from his injuries after the shooting.